MONDAY, July 2 (HealthDay News) -- New research suggests pregnant mothers who take certain antipsychotic drugs may face a higher risk of gestational diabetes, which can appear
during pregnancy.

Gestational diabetes involves high blood sugar that starts or is first diagnosed during pregnancy. According to the U.S. National Institutes of Health, gestational diabetes can pose hazards for both mother and baby.

The new study appears in the July issue of the journal Archives of General Psychiatry.

Until now, "the evidence concerning use of antipsychotics during pregnancy [was] generally lacking or weak," the authors of the new study, led by Dr. Robert Boden of Karolinska Institutet and Uppsala University, both in Sweden, noted in a journal news release.

The researchers studied medical records of Swedish people, focusing on hundreds of thousands of women who gave birth between July 2005 and December 2009.

Gestational diabetes was more than twice as common (4.3 percent vs. 1.7 percent) in women who filled prescriptions for antipsychotics, the researchers reported. The study did not, however, prove the antipsychotics directly increased the risk of gestational diabetes.

"Maternal use of antipsychotics during pregnancy ... is associated with an increased risk of gestational diabetes," the authors wrote. "Pregnant women treated with antipsychotics should be closely monitored for gestational diabetes and deviating fetal growth."

One expert in the United States agreed that there has been "a paucity of information" about potential links between these drugs and diabetes in pregnancy.

"However, this study and others recently have suggested that the use of antipsychotics during pregnancy is not as free of risk as traditionally thought," said Dr. Bryan Bruno, acting chairman of the department of psychiatry at Lenox Hill Hospital in New York City.

"The peak age of onset of schizophrenia in women is 25 to 35 years old, which are also the peak childbearing years," he said. "Women with psychotic illnesses are likely to have more unplanned pregnancies than women without a psychotic illness."

"Obviously, if a patient can do without the medication, it would be appropriate to discontinue it," Bruno said. "But this is frequently not the case, and these decisions have to be made on a case-by-case basis weighing the relative risks versus benefits."

"With limited research data on the impact of newer atypical antipsychotics during pregnancy, pregnant women with bipolar disorder or schizophrenia may be better off with the older antipsychotics," he added. He said the reproductive-safety data on older antipsychotics is more robust and reassuring than it is for newer drugs.